Biological and biochemical effects of the microbial insecticide mycotal and linseed oil on the pink bollworm Pectinophora Gossypiella (Saund)‎

Abstract EN

Entomopathogenic fungi Verticillium lecanii and linseed oil were used alone or in sequence to evaluate their direct and latent effect on newly hatched larvae of susceptible strain of the Pectinophora gossypiella (Saund.) under constant conditions 26±1Co and 80-85 % RH.

LC50 & LC 25 values for these two materials were estimated which was 1.5 x 10 7& 0.5x10 7 spores for V.

Lecanii and 4ml & 2ml for linseed oil.

Percentage of larval, pupal mortality and adult emergence were estimated.

The latent effect of the survived larvae was considered and the obtained results could be summarized as follows: V.

lecanii, linseed oil, or both produced mortality after 1 day, ranging between 1.8 and 37%.

PBW neonate was more sensitive to linseed oil than to V.

lecanii.

Larval period was 15.35, 17.79 and 18.16 days, respectively, when neonate was fed on V.

lecanii, linseed oil and the sequence treatment compared with 12.3 days for untreated control.

Pupal duration increased significantly in all treatments.

Fungi and linseed oil treatments prolonged larval and pupal durations and shortened the adult stages.

Weights of 4th instar larvae resulted from the V.

Lecanii /line seed oil treatment were greatly reduced to 0.009 mg, while increased to 0.034 mg for larvae treated with linseed oil.

Also, pathogenic fungi, sequence treatment followed by linseed oil alone affected on some biological characters such as fecundity of emerged females, eggs hatchability percentage and longevity of males and females.

In addition, carbohydrate hydrolyzing enzymes, tranamenase enzymes, total soluble protein & total lipid were affected after 10 days of treatment of the newly hatched larvae.